1. Field of the Invention
The present invention relates to an ATM (Asynchronous Transfer Mode) exchange, and, more particularly, to an ATM exchange which can connect a terminal requesting connection (hereinafter called "connection requesting terminal") to a terminal other than a terminal which is the target for the requested connection (hereinafter called "connection requested terminal") when the connection requesting terminal cannot be connected to the connection requested terminal.
2. Description of the Related Art
An ATM exchange holds a network having a plurality of terminals connected thereto or directly accommodates terminals, and connects a connection requesting terminal to a connection requested terminal by executing predetermined call connection procedures in response to a call connection request made by the connection requesting terminal. This call connection procedures are performed based on call transfer conditions given from the connection requesting terminal (calling terminal) or a network, such as the required bandwidth and the identifier (ID) of the connection requested terminal. Specifically, the ATM exchange connects the connection requesting terminal to the connection requested terminal only when the bandwidth which satisfies the given call transfer conditions can be secured. This connecting scheme is generally called "receiving control."
When such terminating control result in a failure to secure the bandwidth which satisfies the given call transfer conditions, the ATM exchange cannot connect the connection requesting terminal to the connection requested terminal. In such a case, however, the purpose of communication intended by the user of the connection requesting terminal (caller) may be achieved even when the connection requesting terminal is connected to a terminal other than the intended connection requested terminal. For medical cases, for example, when the terminal of one patient requests connection to a terminal on an intended medical organization X but is not connected to such a terminal, the terminal of the patient would be better connected to a terminal of another medical organization Y than not connected at all.